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(No Model.) I

G. W. DUDLEY.

REAMER.

No. 258,390. Patented May 23, 1882.

ATTORNEYS.

ITE STATES GEORGE W. DUDLEY, OF WAYNESBOROUGH, ASSIGNOR TO HIMSELF AND J. MARSHALL McOUE,

OF AFTON, VIRGINIA.

REAMER.

SPECIFICATION forming part of Letters Patent No. 258,390, dated May 23,1882.

Application filed August 16, 1881. (No model.)

To all whom it may concern:

Be it known that I, GEORGE W. DUDLEY, of Waynesborough, in the county of Augusta and State of Virginia, have invented a new and Improved Reamer; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being bad to the accompanying drawings, forming part of this specification, in which-- Figure 1 is a side view representing the reamer with the grooves cut in it before it is twisted. Fig. 2 represents a side view of the reamer complete; and Figs. 3 and 4are crosssections, respectively, through thelines m0 and y y, looking in the direction of the arrows.

My invention relates to an improvement in that class of tools known as reamers, and it consistsin a tapered polygonal piece of metal having flat sides with a groove on one side of each of its corners and then twisted to form a spiral cutting-edge, as hereinafter more fully described.

In the drawings, A represents the reamer, which, as shown, is made in the shape of a square in cross-section,having four flat sides with a groove, a, cut in each of its sides upon one side of its corner angles. This reamer is first made in the square shape with the proper amount of taper, the grooves a then cut, and

0 the proper amount of pitch or spiral twist then given to the cutting-edges by twisting the whole piece. it is turned about itslongitudinal axis, so that its spirals wind reversely to those of the ordi- 3 5 nary bit or gimlet, by which structure it has in use, when turned to the right in the usual way, a tendency to throw the reamer up or out of the work, instead of drawing it in.

The advantages of thisform of reamer are-- First, as it cuts at all points in the circum- In giving the twist to the reamer.

ference at the same time, it makes a perfectlyround hole.

Second, it will not choke, as it drives the cuttings before it.

Third, it cannot get tight in the hole, as the 5 twist is in theopposite direction to that usually employed.

Fourth, it cannot jar in cutting, as it cuts directly against the pressure.

Fifth, it makesadraw out, and consequently cuts faster than any other shape, while the cutting-edge, for the same reason, will last infinitely longer.

Sixth, having flat sides, it can be ground on an emery-wheel, which is not the case with any fluted reamer.

Seventh, it is as easily manufactured as the flat reamer by first forging it square, grooving the corners, twisting, turning it on the lathe, and grinding it.

I am aware of the fact that spirally-fluted reamers having the twist in the same direction as mine have been heretofore made. My invention, however, is distinctive in the respect that the sides of the reamer are per- 6 fectly flat, thus permitting the edges to be ground by an emery-wheel, while the required acuteness is given to the cutting angles by the grooves at the sides of the corners, makin gan easily-constructed and very effective tool for the purpose.

Having thus described my invention, what I claim as new is- A reamer made with flat tapered sides, grooved at the corners, and twisted, substantially as shown and described.

GEORGE WILSON DUDLEY.

Witnesses:

R. F. WAY, I. S. WALLACE. 

